(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
AW[cq][eq][br][fr][gr]AB[co][bq][fq][er]C[Neither the cross-cut nor the extension work for Black.]
(;B[cr]
;W[dr]C[Double atari!])
(;B[dr]
;W[dq]
;B[cr]
;W[bp]
;B[bs]
;W[ar]
;B[cp]
;W[es]
;B[ep]
;W[aq]
;B[dp]
;W[bq]
;B[bo]
;W[ds]
;B[cs]
;W[as])
(;B[dq]C[This is the solution. Black can force.]
;W[ep]
;B[cr]C[..and force again.]
;W[cp]
(;B[ar]
;W[bs]
;B[cs]
;W[es]
(;B[as]C[This would be a mistake.]
;W[bp]
;B[ap]
;W[bo]
;B[ao]
;W[bn]
;B[an]
;W[am]
;B[aq]
;W[bm]C[Only one eye.])
(;B[bp]
;W[dp]
;B[as]
;W[bo]
;B[bn]
;W[ao]
;B[an]))
(;B[bs]
;W[ar]
;B[aq]
;W[es]
;B[dr]
;W[dp]
;B[as]
;W[ds]
;B[bp]
;W[bo]
;B[bn])
(;B[dp]C[This way is best.]
;W[bp]
;B[bo]
;W[aq]
;B[eo]LB[fp:B][bs:A]C[Next, Black is threatening A or B.]
;W[cs]
;B[fp])))
